Lymphoma is a malignant tumor originating from lymphatic tissue, which can be roughly divided into two types: Hodgkin's lymphoma and non-Hodgkin's lymphoma. It has the characteristics of high recurrence rate, high mortality rate, and short survival time. Tumor cells in lymphoma form a tumor microenvironment (TME) that inhibits host anti-tumor immunity with surrounding immune cells, while tumor-associated macrophages (TAMs) are a key cell in TME. TAMs promote immune evasion of tumor cells in some ways by producing various cytokines and/or abnormal expression of immune checkpoint molecules. Programmed death receptor-1 (PD-1) and its ligand 1 (PD-L1) are important negative regulatory factors for immune cell activation. Recent studies have shown that anti-PD-1/PD-L1 therapy represents a new strategy for lymphoma immunotherapy. This article will focus on the role and expression of TAMs and PD-1/PD-L1 in lymphoma, and explore the efficacy of anti-PD-1/PD-L1 immunotherapy in different types of lymphoma.
Humans ; Immunotherapy ; B7-H1 Antigen/immunology* ; Programmed Cell Death 1 Receptor/immunology* ; Tumor Microenvironment ; Lymphoma/immunology* ; Tumor-Associated Macrophages/immunology*

BACKGROUND: Lung adenocarcinoma (LUAD) remains one of the leading causes of cancer morbidity and mortality worldwide, and its initiation and progression are closely associated with the tumor immune microenvironment. Increasing evidence suggests that environmental exposure is a critical factor influencing lung cancer development. Among these factors, fine particulate matter (PM2.5), a major component of air pollution, has been strongly linked to elevated lung cancer risk and unfavorable prognosis. However, the underlying immunoregulatory mechanisms by which PM2.5 drives LUAD progression remain poorly understood. Tumor-associated macrophages (TAMs), especially those polarized toward the M2 phenotype, are key components of the tumor microenvironment and play crucial roles in tumor growth, angiogenesis, and immune evasion. This study aims to investigate the effects of PM2.5 exposure on TAMs and to identify the key pro-tumorigenic factors mediating this process. METHODS: A mouse orthotopic lung cancer model under PM2.5 exposure was established to assess lung tumor growth and macrophage phenotypic alterations using in vivo imaging and flow cytometry. A subcutaneous tumor model involving co-inoculated macrophages and tumor cells was used to further verify the effects of PM2.5 on the function of TAMs and tumor malignancy. Combining in vitro experiments, flow cytometry, Western blot, reverse transcription quantitative polymerase chain reaction (RT-qPCR), cell counting kit-8 (CCK-8) assay, colony formation assay, and wound healing assay were employed to evaluate the regulatory effects of PM2.5 on the polarization of bone marrow-derived macrophages (BMDMs) as well as tumor cell proliferation, migration, and colony-forming ability. Transcriptome sequencing integrated with TISIDB (Tumor-immune System Interactions Database) and GEPIA (Gene Expression Profiling Interactive Analysis) databases was performed to identify key cytokines for further functional validation. RESULTS: In the mouse orthotopic lung cancer model, PM2.5 exposure significantly promoted tumor growth and increased the proportion of M2-type TAMs (P<0.05). Subcutaneous co-inoculation with PM2.5-treated BMDMs markedly enhanced tumor proliferation and elevated the intratumoral M2-type TAMs. PM2.5-pretreated BMDMs exhibited an immunosuppressive programmed cell death ligand 1 (PD-L1)+/arginase 1 (Arg1)+ phenotype, and their conditioned media significantly promoted proliferation, migration, and colony formation of Lewis lung carcinoma cells (LLC) and B16 melanoma cells (B16) (P<0.05). Transcriptome analysis revealed that PM2.5 substantially altered macrophage gene expression, with IL-1α identified as a key upregulated secreted cytokine enriched in immunosuppressive related signaling pathways. Clinical database analyses further indicated that IL-1α expression was positively correlated with macrophage and regulatory T cells (Treg) infiltration in the LUAD immune microenvironment, and that high IL-1α expression was associated with worse overall survival in LUAD patients (HR=1.5, P=0.0053). Western blot, RT-qPCR, and immunofluorescence confirmed that PM2.5 exposure significantly upregulated IL-1α expression and secretion in TAMs. CONCLUSIONS PM2.5 exposure facilitates LUAD progression by inducing an immunosuppressive phenotype in macrophages and enhancing the malignant behaviors of tumor cells. Mechanistically, IL-1α may serve as a key pro-tumorigenic cytokine secreted by macrophages under PM2.5 exposure. This study provides new insights into the pathogenesis of PM2.5-associated LUAD and suggests that IL-1α could serve as a potential therapeutic target.
Animals ; Mice ; Tumor-Associated Macrophages/immunology* ; Particulate Matter/toxicity* ; Adenocarcinoma of Lung/metabolism* ; Lung Neoplasms/genetics* ; Humans ; Disease Progression ; Tumor Microenvironment/drug effects* ; Cell Proliferation/drug effects* ; Cell Line, Tumor

Cervical cancer (CC) has been a hot topic in the field of gynecological cancer due to its high morbidity and mortality. As one of the major components, tumor-associated macrophages (TAMs) play a crucial role in the tumor microenvironment (TME), differentiating into M1 and M2 phenotypes under the influence of various cytokines, with a predominance of the M2 phenotype among TAMs. Notably, the functions of these two phenotypes are almost opposite. M1 macrophages promote inflammation and inhibit tumor development, while M2 macrophages tend to suppress the immune response and promote tumor growth. Additionally, TAMs can influence tumor invasion, metastasis and immune regulation through interacting with various lymphocytes and cytokines. Numerous studies have demonstrated that TAMs can be used as prognostic markers for CC, and as therapeutic targets in clinical setting. A deeper comprehension of interactions between TAMs and CC, achieved by integrating findings and conclusions from various studies, is conducive to the discovery of new directions for research and new perspectives for clinical treatment.
Humans ; Uterine Cervical Neoplasms/pathology* ; Female ; Tumor-Associated Macrophages/metabolism* ; Tumor Microenvironment/immunology* ; Disease Progression ; Cytokines/immunology* ; Animals ; Macrophages/immunology*

Patients with ovarian cancer (OC) are often diagnosed at an advanced stage and have a poor prognosis because of extensive tumour metastasis. Tumour metastasis usually occurs in stages, which means that before the invasion of tumour cells, a pre-metastatic niche (PMN) has been formed to support the subsequent colonisation and growth of tumour cells. Tumour-associated macrophages (TAMs) are highly heterogeneous in terms of origin, phenotype and function. As one of the most abundant components in the tumour microenvironment (TME), TAMs can contribute to PMN formation by promoting organotropism, mediating immunosuppression, metabolic reprogramming, facilitating angiogenesis, and inducing cancer cell stemness. Therefore, TAMs play an important role in OC metastasis.
Humans ; Ovarian Neoplasms/immunology* ; Female ; Tumor-Associated Macrophages/immunology* ; Tumor Microenvironment ; Neoplasm Metastasis ; Animals ; Macrophages/metabolism*

Objective To screen the potential key genes of osteosarcoma by bioinformatics methods and analyze their immune infiltration patterns. Methods The gene expression profiles GSE16088 and GSE12865 associated with osteosarcoma were obtained from the Gene Expression Omnibus(GEO),and the differentially expressed genes(DEGs)related to osteosarcoma were screened by bioinformatics tools.Gene Ontology(GO)annotation,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment,and analysis of immune cell infiltration were then carried out for the DEGs.The potential Hub genes of osteosarcoma were identified by protein-protein interaction network,and the expression of Hub genes in osteosarcoma and normal tissue samples was verified via the Cancer Genome Atlas(TCGA). Results A total of 108 DEGs were screened out.GO annotation and KEGG pathway enrichment revealed that the DEGs were mainly involved in integrin binding,extracellular matrix (ECM) structural components,ECM receptor interactions,and phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt)signaling pathway.Macrophages were the predominant infiltrating immune cells in osteosarcoma.Secreted phosphoprotein 1(SPP1),matrix metallopeptidase 2(MMP2),lysyl oxidase(LOX),collagen type V alpha(II)chain(COL5A2),and melanoma cell adhesion molecule(MCAM)presented differential expression between osteosarcoma and normal tissue samples(all P<0.05). Conclusions SPP1,MMP2,LOX,COL5A2,and MCAM are all up-regulated in osteosarcoma,which may serve as potential biomarkers of osteosarcoma.Macrophages are the key infiltrating immune cells in osteosarcoma,which may provide new perspectives for the treatment of osteosarcoma.
Bone Neoplasms/immunology* ; Computational Biology/methods* ; Gene Expression Profiling/methods* ; Humans ; Osteosarcoma/immunology* ; Phosphatidylinositol 3-Kinases/genetics* ; Tumor-Associated Macrophages/immunology*

Objective: The aim of this study was to explore the effects of 2-hexyl-4-pentylenic acid (HPTA) in combination with radiotherapy (RT) on distant unirradiated breast tumors. Methods: Using a rat model of chemical carcinogen (7,12-dimethylbenz[a]anthracene,DMBA)-induced breast cancer, tumor volume was monitored and treatment response was evaluated by performing HE staining, immunohistochemistry, immunofluorescence, qRT-PCR, and western blot analyses. Results: The results demonstrated that HPTA in combination with RT significantly delayed the growth of distant, unirradiated breast tumors. The mechanism of action included tumor-associated macrophage (TAM) infiltration into distant tumor tissues, M1 polarization, and inhibition of tumor angiogenesis by IFN-γ. Conclusion The results suggest that the combination of HPTA with RT has an abscopal effect on distant tumors
Animals ; Antineoplastic Agents/therapeutic use* ; Cell Proliferation/radiation effects* ; Combined Modality Therapy ; Cytokines/immunology* ; Fatty Acids, Unsaturated/therapeutic use* ; Female ; Mammary Neoplasms, Experimental/radiotherapy* ; Rats ; Tumor-Associated Macrophages/radiation effects*